Syringes generally comprise an elongate single piece plunger rod disposed in a barrel. Generally, the plunger rod is of one piece construction. Syringes that have breakable plunger rods, which break upon application of force into two or more pieces, have been used to prevent reuse of syringes. However, such syringes in which the plunger rod breaks into pieces renders the syringe assembly inoperable because the plunger rod can no longer be advanced within the barrel of the syringe.
In applications where the syringe is prefilled with fluid and then packaged for delivery to the user, the length of the single piece plunger rod must be at least long enough to accommodate the full length of the barrel. Such prefilled syringes act as the storage container for the fluid and must be packaged in such a way to accommodate the prefilled syringe barrel and its full length single piece plunger rod.
While there are a variety of syringe designs available, alternative syringe and plunger rod designs are desirable for various applications and to reduce costs associated with manufacturing and packaging of medical devices.